Module

PadicFiniteTypeRoots.lean

Nyll.Yamaguchi26AbfaithfulGalois.FieldExamples.PadicFiniteTypeRoots
3 declarations indexed from sourceView source ↗

Roots of unity in finitely generated p-adic extensions

Finite extensions of the p-adic field have finite torsion unit groups. The same finiteness holds in essentially finite-type extensions by passing to their finite extension of algebraic constants.

Declarations

Yamaguchi26AbfaithfulGalois.padicCompleteDVF_residue_char
Source context 3 commands

Surrounding namespaces, section variables, and local commands at this declaration.

namespace Yamaguchi26AbfaithfulGalois
open LocalFieldTheory.DiscreteValuationField.Examples.Qp
universe u
theorem padicCompleteDVF_residue_char (p : ℕ) [Fact p.Prime] :
    CharP (padicCompleteDVF p).residueField p
Yamaguchi26AbfaithfulGalois.finite_torsion_finiteExtension_padic

Finite extensions of Q_p have finite torsion units, via their actual residue field.

Source context 3 commands

Surrounding namespaces, section variables, and local commands at this declaration.

namespace Yamaguchi26AbfaithfulGalois
open LocalFieldTheory.DiscreteValuationField.Examples.Qp
universe u
theorem finite_torsion_finiteExtension_padic
    (p : ℕ) [Fact p.Prime] (C : Type u) [Field C] [Algebra (Padic p) C]
    [FiniteDimensional (Padic p) C] : Finite (CommGroup.torsion Cˣ)
Yamaguchi26AbfaithfulGalois.finite_torsion_of_essFiniteType_padic

Roots of unity in a finitely generated Q_p-extension lie in its finite extension of algebraic constants.

Source context 3 commands

Surrounding namespaces, section variables, and local commands at this declaration.

namespace Yamaguchi26AbfaithfulGalois
open LocalFieldTheory.DiscreteValuationField.Examples.Qp
universe u
theorem finite_torsion_of_essFiniteType_padic
    (p : ℕ) [Fact p.Prime] (E : Type u) [Field E] [Algebra (Padic p) E]
    [Algebra.EssFiniteType (Padic p) E] : Finite (CommGroup.torsion Eˣ)